Background: The predictive factors for lateral neck lymph node metastasis (LLNM) in papillary thyroid microcarcinoma (PTMC) remain undetermined. This study investigated the clinicopathological characteristics, transcriptomes, and tumor microenvironment in PTMC according to the LLNM status. We aimed to identify the biomarkers associated with LLNM development. Methods: We retrospectively reviewed the medical records of patients with PTMC from two independent institutions between 2018 and 2022 (n=597 and n=467). We compared clinicopathological features between patients without lymph node metastasis (N0) and those with LLNM (N1b). Additionally, laser capture microdissection and RNA sequencing were performed on primary tumors from both groups, including metastatic lymph nodes from the N1b group (n=30; 20 primary tumors and 10 paired LLNMs). We corroborated the findings using RNA sequencing data from 16 BRAF-like PTMCs from The Cancer Genome Atlas. Transcriptomic analyses were validated by immunohistochemical staining. Results: Clinicopathological characteristics, such as male sex, multifocality, extrathyroidal extension, lymphatic invasion, and central node metastasis showed associations with LLNM in PTMCs. Transcriptomic profiles between the N0 and N1b PTMC groups were similar. However, tumor microenvironment deconvolution from RNA sequencing and immunohistochemistry revealed an increased abundance of tumor-associated macrophages, particularly M2 macrophages, in the N1b group. Conclusion Patients with PTMC who have a male sex, multifocality, extrathyroidal extension, lymphatic invasion, and central node metastasis exhibited an elevated risk for LLNM. Furthermore, infiltration of M2 macrophages in the tumor microenvironment potentially supports tumor progression and LLNM in PTMCs.

Esophageal perforation can lead to serious complications, and rapid diagnosis and treatment significantly affect the prognosis. Endoscopic vacuum-assisted closure (EndoVAC) therapy is widely accepted as a safe, well-tolerated, effective, versatile and practical procedure for the management of esophageal perforation in selected patients. We report the successful use of EndoVAC therapy for management of an esophageal perforation secondary to foreign body removal. A 56-year-old man presented to the emergency department for evaluation of chest pain after swallowing the plastic shell of a pill. Emergency endoscopy revealed an esophageal wall laceration (approximately 3 cm) and microperforation. The esophageal laceration and microperforation were limited to the mid-esophagus. The patient underwent EndoVAC therapy, which was repeated every 3–4 days for a total of six sessions over a period of 21 days. We observed improvement in the esophageal injury with granulation tissue formation during the fifth session. Subsequent follow-up evaluation, including esophagography and chest computed tomography confirmed complete healing of the esophageal injury. Following resumption of diet, the patienton a was discharged without any complications.

Background: Papillary thyroid carcinoma (PTC) can be classified into two distinct molecular subtypes, BRAF-like (BL) and RASlike (RL). However, the molecular characteristics of each subtype according to clinicopathological factors have not yet been determined. We aimed to investigate the gene signatures and tumor microenvironment according to clinicopathological factors, and to identify the mechanism of progression in BL-PTCs and RL-PTCs. Methods: We analyzed RNA sequencing data and corresponding clinicopathological information of 503 patients with PTC from The Cancer Genome Atlas database. We performed differentially expressed gene (DEG), Gene Ontology, and molecular pathway enrichment analyses according to clinicopathological factors in each molecular subtype. EcoTyper and CIBERSORTx were used to deconvolve the tumor cell types and their surrounding microenvironment. Results: Even for the same clinicopathological factors, overlapping DEGs between the two molecular subtypes were uncommon, indicating that BL-PTCs and RL-PTCs have different progression mechanisms. Genes related to the extracellular matrix were commonly upregulated in BL-PTCs with aggressive clinicopathological factors, such as old age (≥55 years), presence of extrathyroidal extension, lymph node metastasis, advanced tumor-node-metastasis (TNM) stage, and high metastasis-age-completeness of resection- invasion-size (MACIS) scores (≥6). Furthermore, in the deconvolution analysis of tumor microenvironment, cancer-associated fibroblasts were significantly enriched. In contrast, in RL-PTCs, downregulation of immune response and immunoglobulin-related genes was significantly associated with aggressive characteristics, even after adjusting for thyroiditis status. Conclusion The molecular phenotypes of cancer progression differed between BL-PTC and RL-PTC. In particular, extracellular matrix and cancer-associated fibroblasts, which constitute the tumor microenvironment, would play an important role in the progression of BL-PTC that accounts for the majority of advanced PTCs.

Background/Aims: There are no data regarding the association between sarcopenic obesity status and nonalcoholic fatty liver disease (NAFLD) and NAFLD-associated liver fibrosis. Therefore, we aimed to investigate the relationship between sarcopenic obesity status (sarcopenia only, obesity only, and sarcopenic obesity) and NAFLD and liver fibrosis in Korean adults. Methods: In total, 2,191 subjects completed a health checkup program, including abdominal ultrasonography and FibroScan. Subjects were classified into the following four categories: optimal body composition (nonobese and nonsarcopenic), sarcopenia only (nonobese), obesity only (nonsarcopenic), and sarcopenic obesity. Sarcopenic obesity was stratified by the skeletal muscle mass index and body fat using bioelectrical impedance analysis. NAFLD was diagnosed by ultrasonography, and liver fibrosis was assessed using transient elastography in subjects with NAFLD. Results: The prevalence of NAFLD and liver fibrosis significantly increased according to the sarcopenic obesity status. In the logistic regression analysis, after adjusting for multiple risk factors, the odds ratio (OR) for the risk of NAFLD was largest in the sarcopenic obesity group (OR, 3.68; 95% confidence interval [CI], 2.94 to 4.60), followed by the obesity only (OR, 2.25; 95% CI, 1.67 to 3.03) and sarcopenia only (OR, 1.92; 95% CI, 1.30 to 2.84) groups, when compared with the optimal group. Additionally, liver fibrosis was independently associated with sarcopenic obesity status (OR 4.69, 95% CI 1.95 to 11.29; OR 4.17, 95% CI 1.56 to 11.17; OR 3.80, 95% CI 0.86 to 16.75, respectively). Conclusions These results demonstrated that sarcopenic obesity was independently associated with NAFLD and liver fibrosis and increased the risk of NAFLD and liver fibrosis more than obesity or sarcopenia alone.

Purpose: The isocitrate dehydrogenase (IDH) family plays an essential role in metabolism and energy production. The relative expression levels of IDH isoforms (IDH1, IDH2, and IDH3) have prognostic significance in several malignancies, including breast carcinoma. However, the IDH isozyme expression levels in different cancer stages and types have not been determined in breast carcinoma tissues. Methods: We analyzed the messenger RNA (mRNA) and protein levels of IDH (IDH1, IDH2, and IDH3A) and α-ketoglutarate (α-KG) in 59 breast carcinoma tissues. Results: The mRNA level of IDH2 was significantly increased at stages 2 and 3 in triple-negative and (ER-/PR-/HER+) breast cancers. However, the elevated α-KG level was only observed in stages 2 and 3, with no differences in the various breast carcinoma types. Western blotting analysis showed that IDH2 protein expression increased in the patient tissues and cell lines. An in vitro study showed IDH2 downregulation in the triple-negative breast cancer cell line MDA-MB-231 that inhibited cell proliferation and migration and induced cell cycle arrest in the G0/G1 phase. Conclusion These findings suggest that different from IDH1 and IDH3, IDH2 is more highly expressed in stages 2 and 3 breast cancer tissues, especially in triple-negative breast cancer. IDH2 potentially serves as a target to detect unknown mechanisms in breast cancer.

We aimed to review the current data composition of the Korean Tuberculosis and Post-Tuberculosis Cohort, which was constructed by linking the Korean Tuberculosis Surveillance System (KNTSS; established and operated by the Korean Disease Control and Prevention Agency since 2000) and the National Health Information Database (NHID; established by the National Health Insurance Service in 2012). The following data were linked: KNTSS data pertaining to patients diagnosed with tuberculosis between 2011 and 2018, NHID data of patients with a history of tuberculosis and related diseases between 2006 and 2018, and data (obtained from the Statistics Korea database) on causes of death. Data from 300 117 tuberculosis patients (177 206 men and 122 911 women) were linked. The rate of treatment success for new cases was highest in 2015 (86.7%), with a gradual decrease thereafter. The treatment success rate for previously treated cases showed an increasing trend until 2014 (79.0%) and decreased thereafter. In total, 53 906 deaths were confirmed among tuberculosis patients included in the cohort. The Korean Tuberculosis and Post-Tuberculosis Cohort can be used to analyze different measurement variables in an integrated manner depending on the data source. Therefore, these cohort data can be used in future epidemiological studies and research on policy-effect analysis, treatment outcome analysis, and health-related behaviors such as treatment discontinuation.

Purpose: Tumor size and lymph node metastasis are important factors that contribute to the progression of breast cancer. We aimed to analyze the relationship between tumor size and lymph node metastasis molecular subtype and examine the effects of nodal metastasis on overall survival (OS). Methods: We retrospectively reviewed the data of 16,552 patients who underwent breast surgery in Samsung Medical Center between 2000 and 2015. Information on tumor size (largest diameter of the invasive component), number of positive lymph nodes, and molecular subtype were obtained. We constructed a linear regression model to evaluate the relationship between tumor size and lymph node metastasis. To determine the effect of nodal metastasis on OS, we performed a Cox proportional regression analysis with Np/T (number of metastatic lymph nodes [n]/tumor size [cm]). Results: This study included 12,007 patients with a median follow-up of 62 months. The linear regression coefficients were 1.043 for luminal A, 1.024 for luminal B, 0.656 for HER2, and 0.435 for triple-negative breast cancer (TNBC) subtypes. No significant difference was observed in the coefficients between the luminal A and B subtypes (p = 0.797), while all other coefficients showed significant difference. After adjusting for other risk factors, the hazard ratio (HR) of Np/T for each subtype was significant for OS: luminal A (HR, 1.134; 95% confidence interval [CI], 1.097–1.171; p < 0.001), luminal B (HR, 1.049; 95% CI, 1.013–1.086;p = 0.007), HER2 (HR, 1.069; 95% CI, 1.014–1.126; p = 0.013), and TNBC (HR, 1.038; 95% CI, 1.01–1.067; p = 0.008). Conclusion The incidence of lymph node metastasis differed according to molecular subtype. Luminal types have higher incidence of nodal metastasis than HER2 and TNBC. The HR of Np/T was highest in luminal A subtypes and lowest in TNBC subtypes.

Purpose: Tumor size and lymph node metastasis are important factors that contribute to the progression of breast cancer. We aimed to analyze the relationship between tumor size and lymph node metastasis molecular subtype and examine the effects of nodal metastasis on overall survival (OS). Methods: We retrospectively reviewed the data of 16,552 patients who underwent breast surgery in Samsung Medical Center between 2000 and 2015. Information on tumor size (largest diameter of the invasive component), number of positive lymph nodes, and molecular subtype were obtained. We constructed a linear regression model to evaluate the relationship between tumor size and lymph node metastasis. To determine the effect of nodal metastasis on OS, we performed a Cox proportional regression analysis with Np/T (number of metastatic lymph nodes [n]/tumor size [cm]). Results: This study included 12,007 patients with a median follow-up of 62 months. The linear regression coefficients were 1.043 for luminal A, 1.024 for luminal B, 0.656 for HER2, and 0.435 for triple-negative breast cancer (TNBC) subtypes. No significant difference was observed in the coefficients between the luminal A and B subtypes (p = 0.797), while all other coefficients showed significant difference. After adjusting for other risk factors, the hazard ratio (HR) of Np/T for each subtype was significant for OS: luminal A (HR, 1.134; 95% confidence interval [CI], 1.097–1.171; p < 0.001), luminal B (HR, 1.049; 95% CI, 1.013–1.086;p = 0.007), HER2 (HR, 1.069; 95% CI, 1.014–1.126; p = 0.013), and TNBC (HR, 1.038; 95% CI, 1.01–1.067; p = 0.008). Conclusion The incidence of lymph node metastasis differed according to molecular subtype. Luminal types have higher incidence of nodal metastasis than HER2 and TNBC. The HR of Np/T was highest in luminal A subtypes and lowest in TNBC subtypes.

Purpose: Although metastasis occurs in 1 or 2 sentinel lymph nodes (SLNs), axillary lymph node dissection (ALND) has been widely not performed. For axillary staging and management, the necessity of intraoperative frozen section analysis of SLN has been controversial. The aim of this study is to evaluate the validity and benefit of SLN analysis by permanent section alone in clinically negative lymph node breast cancer patients. Methods: We conducted a retrospective study of 283 cases with negative node clinical findings between July 2018 and August 2019 in Samsung Medical Center. Clinical nodal stage was evaluated by physical examination, breast ultrasonography, breast magnetic resonance imaging, and chest computerized tomography. The cases were divided into 2 groups; the permanent group had 151 cases (53.4%) and the frozen group had 132 cases (46.6%). We retrospectively analyzed the differences in the number of metastatic lymph nodes and rates of performed ALND between the 2 groups. Results: Baseline and clinicopathologic characteristics between the 2 groups were well balanced. Three cases in the permanent group and 6 cases in the frozen group underwent additional or immediate ALND. The rates of ALND between the 2 groups were not significantly different (P = 0.312). The cased of 78.9% and 89.5% with metastatic lymph nodes in permanent and frozen groups were in the pathologic N1 stage, respectively. Conclusion SLNs analysis by permanent section alone may be performed in clinically negative axillary node breast cancer patients. Our findings can help to avoid unnecessary intraoperative frozen section analysis.

As of April 18, 2020, there have been a total of 10,653 confirmed cases and 232 deaths due to coronavirus disease 2019 (COVID-19) in Korea. The pathogen spread quickly, and the outbreak caused nationwide anxiety and shock. This study presented the anecdotal records that provided a detailed process of the multidisciplinary teamwork in mental health during the COVID-19 outbreak in the country. Psychosocial support is no less important than infection control during an epidemic, and collaboration and networking are at the core of disaster management. Thus, a multidisciplinary team of mental health professionals was immediately established and has collaborated effectively with its internal and external stakeholders for psychosocial support during the COVID-19 outbreak.